The side with more bass is leaking/venting from the back-cup.Hi!
I bought a used LCD-XC in pristine conditions.
Despite this my headphone have a strange channel imbalance only on bass between 20 to 50Hz.
Left sub bass is 1.4/1.5dB more than right.
Earpads are slightly soft now.
I measured this on a flat plane with proper precautions.
Does anyone exibit the same behaviour?
From Amirm measurements seems the same.
Measurements attached.